Added some thoughts on the main README.

[KriSun95]

Some additions to the README from our discussion. I have either taken a go at making the change myself or at least edited the lines to leave more of a comment on where I was confused. Feel free to delete the latter edits and replace with your own ones that actually add to the documentation.

[thanasipantazides]

@KriSun95 I just updated the README based on your comments. Very helpful, thank you!

Changes:

1. There's an test (bin/test_buffers) you can run just to validate the build. Instructions for running and expected output are now in the README.
2. Wording changes based on your suggestions, (hopefully) clearer overview of systemctl usage, and added debugging info for the Address already in use error and the fstab problems.
3. Hopefully fixed issue Building the docs #79. Please let me know if building docs works for you now.